This invention relates to high vacuum components and, more particularly, to a door for an ultra-high vacuum chamber or the like which can be baked or otherwise subjected to high temperatures without leaking, and yet provides quick and simple access to the chamber. There are many uses to which high and ultra-high vacuum systems, i.e., systems capable of producing and maintaining vacuums of 10.sup.-6 torr or higher, are put in which it is necessary or desirable to raise the temperature of various ones of the system components up to 250.degree. C. or more. For example, it is often necessary in order to achieve a desired ultra-high vacuum that the vacuum chamber be out-gassed by baking. Also, components of ultra-high vacuum furnaces must be capable of withstanding a high furnace temperature without the integrity of the vacuum being adversely affected. It will be recognized that the seals where various components of the system are joined together are particularly vulnerable to leaks. However, vacuum joints have been designed and developed which solve the majority of such problems. For example, the vacuum joint described and claimed in U.S. Pat. No. 3,208,758 is widely used to create a good hermetic seal between vacuum members, such as flanges, which are bolted together. With use of a metal gasket, such a joint is bakeable or, in other words, capable of withstanding high temperature operations and cycling without either out-gassing or leaking.
Neither the vacuum joint arrangement described above nor other vacuum joints now available are really suitable, however, for use with doors for chamber access ports which require continual use. In this connection, generally all of such vacuum joints require the use of a multitude of closely spaced bolts or the like around the periphery of the seal to develop the relatively high and uniform pressure between the joint members required for a vacuum-tight seal capable of withstanding high temperature baking. It will be recognized that the necessity of removing and then reapplying such bolts whenever it is desired to have access through a vacuum port protected by such a seal makes access through such a port a relatively long and tedious process. The increasingly wide usage of ultra-high vacuum systems for batch processing in the integrated circuit field, surface research, and high temperature applications has added impetus to the need for quick and relatively easy access into a bakeable vacuum chamber.